1. Field of the Invention
The present invention relates to a heat-pump-type water heater provided with a heat-pump-type refrigeration cycle and used to supply hot water that can also be used for heating.
2. Description of the Related Art
A heat pump system is becoming widespread. The heat pump system has a water heat exchanger, which has replaced an air heat exchanger. The heat pump system is constructed separately from an outdoor machine. Jpn. Pat. Appln. KOKAI Publication No. 2001-082818, for example, discloses a heat pump system and a heat pump system installation method. As use side units, this heat pump system allows the functions of hot water supply, reheating of bathtub water by a circulation pump, air conditioning, etc., and the number of units can be decreased or increased. The configuration of the system is relatively simple and allows the use of an existing unit.
Specifically, this heat pump system includes: an outdoor unit having a compressor, outdoor heat exchanger, and electronic expansion valve; a hot water storage unit having a hot water storage tank connected to the outdoor unit by means of a refrigerant pipe, and a water heat exchanger for hot water supply; a reheating unit having a heat exchanger for reheating, which is connected to the outdoor unit via the hot water storage unit by means of the refrigerant pipe; and an air conditioning unit for heating, which is connected to the outdoor unit via the hot water storage unit by means of the refrigerant pipe.